Wound treatment apparatus

ABSTRACT

A control system for use with a vacuum bandage over a wound includes a vacuum pump, a waste canister operably coupled to the pump, and a fluid source. The canister is coupled to the bandage such that, when a vacuum is applied to the canister, the vacuum is applied to the bandage. The fluid source is coupled to the bandage to selectively introduce fluid into the wound.

RELATED APPLICATIONS

[0001] The present disclosure is based upon U.S. Provisional applicationSer. No. 60/167,753, filed on Nov. 29, 1999, the complete disclosure ofwhich is hereby expressly incorporated by reference.

TECHNICAL FIELD

[0002] The present invention relates to wound treatment apparatus foruse with vacuum bandages of the type that dispenses fluid to a wound anddraws fluid away from the wound.

BACKGROUND AND SUMMARY

[0003] Medical professionals, such as nurses and doctors, routinelytreat patients having surface wounds of varying size, shape, andseverity. It is known that controlling the topical atmosphere adjacent awound can enhance the healing process. For example, by applyingmedicinal agents or even water over a wound, dirt and bacteria areeither killed or washed away, thereby promoting healing. In addition,applying a negative pressure or vacuum to a wound draws out exudate,which might contain dirt and bacteria, from the wound to further promotehealing.

[0004] Conventional treatment of a surface wound involves placement of apacking or dressing material, such as cotton, gauze, or otherbandage-like material directly in contact with the patient's wound.Often there is a need to change the dressing material frequently becauseit becomes saturated with exudate discharged from the wound. Somedressings include an apparatus attached thereto for applying a vacuumthrough the bandage to the wound to draw exudate and promote healing.These bandages, however, need to be changed often so medicinal fluidscan be applied to the wound, or because the bandage is soiled.

[0005] Changing vacuum bandages, however, poses several potentialproblems for the patient. Inadvertent contact with sensitive tissuewithin and adjacent the wound may cause significant discomfort to thepatient, as well as further trauma to the wound. In addition, exposingthe wound to the open atmosphere can increase the chance of infection.

[0006] Medical caregivers and patients both would benefit from anapparatus that would dispense fluid into a wound, and draw the fluid andexudate from the wound without having to change the bandage covering thewound. It would be a further benefit to the caregiver if the apparatusprovided a collection unit to store the discharged material, and thatunit could be disposed of in a sanitary manner. In addition, because itis well known that patients often suffer from more than one wound,patients would benefit from an apparatus that can treat two woundssimultaneously and independently.

[0007] Accordingly, an illustrative embodiment provides a control systemfor use with a bandage of the type which covers a wound and within whicha vacuum is formed in a space above the wound. The control systemcomprises a vacuum pump, a waste canister, a fluid source and a drive.The waste canister is operably coupled to the pump and the drive isassociated with the fluid source. The canister is coupled to the bandagesuch that, when a vacuum is applied to the canister, the vacuum isapplied to the bandage. The fluid source is coupled to the bandage suchthat, when the drive is energized, fluid is introduced into the wound.

[0008] Further illustrative embodiments comprise a syringe having aplunger coupled to the control system as the fluid source. Anillustrative drive comprises a motor and a plunger interface movable bythe motor to drive the plunger. Illustratively, the motor is operativelycoupled to a lead screw to rotate the lead screw. The lead screw isoperatively coupled to the plunger interface to move the plungerinterface to drive the plunger and expel the fluid. In otherillustrative embodiments, the fluid source is a container or bagcontaining fluid and held at an elevated position to provide irrigationthrough the control system to the bandage.

[0009] Additional embodiments may include the waste canister being adisposable waste canister.

[0010] Another illustrative embodiment further provides a control systemthat comprises two such vacuum pumps, two such waste canisters, two suchfluid sources and two such drivers for use with two such bandages fordual vacuum therapy and irrigation systems. The controller providesindependent operation of the dual systems.

[0011] Another illustrative embodiment of the control system provides ahousing, a controller, a pair of vacuum pumps, a pair of syringe mounts,a pair of syringe drives, and a pair of waste canister mounts, a pair ofwaste canisters and a pair of syringes. The controller is configured toprovide independent operation of each of the vacuum pumps. Each of thecanisters is removably attached to one of the canister mounts, and eachis in communication with a bandage and one of the vacuum pumps. Each ofthe syringes is removably attached to one of the syringe mounts, and incommunication with the bandage.

[0012] Further illustrative embodiments of the control system include apair of sensors configured to determine the amount of fluid in each ofthe syringes. Another pair of sensors is provided each configured todetermine the position of the plunger of one of the syringes.

[0013] Another illustrative embodiment of the control system provides aconnector for each of the waste canisters, allowing operation of thecontroller when at least one of the waste canisters is coupled to one ofthe waste canister mounts. Each connector is configured to suspendoperation of the controller when at least one of the waste canisters isremoved from one of the waste canister mounts. Illustrative embodimentsfurther provide a pair of valves. Each valve connects one of the vacuumpumps to one of the waste canisters. Each valve is adjustable toestablish the level of vacuum in each of the canisters. A pair of vacuumregulators is also provided, each coupled to one of the valves. Each ofthe regulators is configured to define a maximum level of vacuum. Eachof the regulators also comprises an air intake for supplying additionalair to one of the pumps. A pair of transducers is provided each coupledbetween one of the valves and waste canisters for measuring vacuum.

[0014] Additional features and advantages of the apparatus will becomeapparent to those skilled in the art upon consideration of the followingdetailed descriptions exemplifying the best mode of carrying out theapparatus as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The illustrative apparatus will be described hereinafter withreference to the attached drawings, which are given as non-limitingexamples only, in which:

[0016]FIG. 1 is a perspective view of a wound treatment apparatuscoupled to a bandage attached to a patient;

[0017]FIG. 2 is a block diagram of the wound treatment apparatus of FIG.1;

[0018]FIG. 3 is a schematic diagram of the wound treatment apparatus ofFIG. 1;

[0019]FIG. 4 is a side cross-sectional view of the wound treatmentapparatus along the lines A-A of FIG. 1;

[0020]FIG. 5 is a schematic block diagram of the vacuum evacuatingsubsystem of the wound treatment apparatus of FIG. 1;

[0021]FIG. 6 is a cross-sectional view of a waste disposal canister ofthe wound treatment apparatus along the lines B-B of FIG. 1;

[0022]FIG. 7 is a partially exploded perspective view of the woundtreatment apparatus of FIG. 1 with the waste canisters removed;

[0023]FIG. 8 is a perspective view of another embodiment of the woundtreatment apparatus;

[0024]FIG. 9 is a side diagrammatic view of the vacuum bandage andportions of the wound treatment apparatus of FIG. 1;

[0025]FIG. 10 is a perspective view of the wound treatment apparatus ofFIG. 1 with the waste cannister removed;

[0026]FIG. 11 is a front elevational view of a waste canister;

[0027]FIG. 12 is a side elevational view of the waste canister of FIG.11; and

[0028]FIG. 13 is a top view of the waste canister of FIG. 11.

[0029] Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates several embodiments of the apparatus, and suchexemplification is not to be construed as limiting the scope of theapparatus in any manner.

DETAILED DESCRIPTION OF THE DRAWINGS

[0030] An embodiment of wound treatment apparatus 2 is shown in FIG. 1.Wound treatment apparatus 2 comprises a central unit housing 4, havingwound treatment systems 6, 8 appended to each side of housing 4. A userinterface 10 is shown positioned between each treatment system 6, 8.Central unit housing 4 is configured to be a portable unit allowing acaregiver to move housing 4 to wherever the patient is located and toclose proximity to the wound or wounds. Housing 4 is shown having ahandle portion 12 to assist the caregiver in moving housing 4. FIG. 1also shows wound treatment system 6 coupled to a bandage 14 attached toa patient's leg 16. Dispensing and evacuating tubes 18, 20 are coupledto both bandage 14 and system 6. Specifically, dispensing tube 18 iscoupled to a luer-lok port 22 extending from syringe 24. Syringe 24 isfilled with a fluid, typically saline, that empties through tube 18 andinto bandage 14, and ultimately onto a wound 300 positioned underbandage 14. (See also FIG. 9.) After contacting wound 300, the fluid andexudate from wound 300 are drawn from bandage 14 through evacuating tube20 and into a waste canister 26 where it is collected. It iscontemplated that the canister 26 can be discarded when filled andreplaced with a new canister 26.

[0031] Apparatus 2 comprises a second system 8 on the opposite side ofhousing 4 from system 6. This configuration allows two wounds to betreated simultaneously with separate bandages, yet, under the control ofa single housing 4. Second bandage 15, as part of system 8, is coupledto dispensing and evacuating tubes 28, 30, respectively, to perform thesame functions as described for system 6. (See FIG. 2.) User interface10 is provided to allow the caregiver to control either or both systems6, 8, to dispense fluid from either or both syringes 24, 224, and toevacuate from either or both bandages 14, 15. It is contemplated thateach wound treatment system 6, 8 will work independent of each other,thus, allowing the caregiver flexibility to apply an appropriate and,yet, possibly different level of treatment to each wound.

[0032] The arrangement of systems 6, 8 relative to user interface 10 onhousing 4 allows convenient interaction between systems 6, 8 and thecaregiver. For example, syringes 24, 224 are conveniently positioned onopposite sides of user interface 10. Each syringe is partially coveredby doors 32, 33 on the front of housing 4. Each door 32, 33 swingsoutwardly about hinges 34, 36, allowing syringes 24, 224 to be removedand replaced. Similarly, waste canisters 26, 27 are each positioned in acavity 9 provided on each side of housing 4. (See FIG. 7.) Each canister26, 27 includes a grip portion 40 for convenient removal andreplacement. Canisters 26, 27 are illustratively secured into eachcavity by a friction fit. (See FIG. 6.) It is appreciated, however, thatsyringes 24, 224 can be secured to other locations on housing 4.

[0033] The portability of apparatus 2 allows a caregiver to position itnear the patient in preparation for treatment wherever the patient islocated. To prepare apparatus 2 for treatment, the caregiver securessyringes 24, 224, which contain fluid, to apparatus 2 in a mannerdescribed in greater detail below. The caregiver then couples tube 18 toport 22 and bandage 14, and tube 20 to bandage 14 and waste canister 26,for treatment of one wound. The caregiver then couples tube 28 to port222 and bandage 15, and tube 21 to bandage 15 and waste canister 27, fortreatment of a second wound. (See also FIG. 2.) The caregiver, throughthe use of user interface 10 can treat the patient by selectivelyirrigating the wounds with fluid and drawing exudate and the fluid fromthe wounds.

[0034] A diagram depicting how wound apparatus 2 operates is shown inFIG. 2. A controller 50 is provided in housing 4 and is an electroniccontrol unit that controls apparatus 2. Controller 50 receives userinput from and provides feedback to user interface 10 through lines 52,54, respectively. It is contemplated that controller 50 will processinformation from both systems 6, 8, and provide appropriate andindependent input to each system. Controller 50 also monitors the statusof all various sensors, and provides input for the valves and motors, asdiscussed in further detail herein. Illustratively, user interface 10 iscomposed of a conventional graphic liquid crystal display (LCD) and amembrane switch panel.

[0035] A power supply 56 provides power to controller 50 and all theattendant systems in housing 4. Power supply 56 can be a conventionalexternal wall socket supply (not shown), or be a battery pack supply(also not shown), or even be variations of both (e.g., a wall socketsupply with a battery pack supply).

[0036] Illustratively, power supply 56 is a medical grade power supplyproviding an output of about 65-watts and a voltage of about 12VDC. Itis contemplated that the power supply can be configured for 120V/60 Hzor 220-240V/50 Hz depending on whether housing 4 is used in America orEurope. Illustratively, the battery power provides the device with powerto operate for about 60 minutes without connection to an external powersource. It is further contemplated that the batteries can berechargeable, and store energy when the device is connected to anexternal wall socket.

[0037] An attitude sensor 58 is provided in communication withcontroller 50 through line 60. Attitude sensor 58 is, illustratively, atilt switch which provides feedback to controller 50. If the switch is,illustratively, in the closed position, controller 50 will continue tooperate, but if the switch opens, controller will shut systems 6, 8down. For example, sensor 58 disables systems 6, 8 if housing 4 tilts ator greater than a predetermined amount, such as 45° from vertical in anydirection.

[0038] It is contemplated that controller 50, user interface 10, powersupply 56, and attitude sensor 58 are all common to and all operate withboth systems 6, 8. Each system 6, 8 further comprises fluid dispensingand vacuum evacuating sub-systems 62, 64 and 66, 68. Fluid dispensingsub-system 62 comprises a syringe 24 having a plunger 70. (See also FIG.4.) Syringe 24 is, illustratively, a standard 60-ml medical syringeutilizing a luer-lok port 22. Plunger 70 is a conventional plunger thatextends into syringe 24 to dispense fluid through luer-lok port 22. Asyringe drive motor 72 is, illustratively, a 12VDC brushless electricmotor or stepper motor configured to provide rotational energy to asyringe drive 74. (See FIG. 4.) When a signal is sent from controller 50along line 76 to syringe drive motor 72, motor 22 applies torque andangular velocity to syringe drive 74 which is, illustratively, a powerscrew 322. (See also FIG. 4.) Power screw 322 translates rotationalmovement of the syringe drive motor 72 into translational movement. Thedrive has a guide 80 to limit a plunger interface 78 to motion along oneaxis. In the illustrated embodiment, syringe drive 72 provides about5.25 inches (13.3 cm) of travel of plunger interface 78, indicated byreference numeral 82, to evacuate the fluid contained in syringe 24.(See also FIG. 4.) Furthermore, syringe drive motor 72 and syringe drive74, as a system, provide about 27 pounds of linear force at a velocityof 1.45 inches (3.7 cm) per second to the plunger interface 78. Theresulting force created by the fluid exiting syringe 24 creates,illustratively, 4-PSIG to 6-PSIG positive pressure at wound 300.

[0039] A syringe home sensor 84 receives information from plungerinterface 78, and provides feedback to controller 50 when syringecapture mechanism 88 reaches its home position 79. A syringe fall travelsensor 86 determines when syringe 24 is fully evacuated by sensing whenplunger interface 78 has reached fall travel. After sensor 86 has beenactivated, controller 50 resets plunger interface 78 to home position 79once syringe 24 is removed.

[0040] Syringe capture mechanism 88 holds syringe 24 in place when thecaregiver places syringe 24 in apparatus 2. (See also FIG. 4.) Capturemechanism 88 is also configured to allow the caregiver to releasesyringe 24 from apparatus 2 when it is empty. Capture mechanism 88further includes a syringe sensor 90 that provides feedback tocontroller 50 through line 92 when syringe 24 is properly held incapture mechanism 88. Controller 50 prevents system 6 from operating ifsensor 90 does not detect syringe 50 being properly held in capturemechanism 88.

[0041] Connectors 94, 96 are provided at opposed ends of dispensing tube18. Either one or both connectors 94, 96, when closed, block flow fromsyringe 24 to bandage 14. Such connectors 94, 96 allow the patient to bedisconnected from apparatus 2 without having to remove bandage 14 oreven shut apparatus 2 down.

[0042] A manual port 98 is also attached to dispensing tube 18 by anauxiliary tube 100. Port 98 permits the caregiver to attach a dispensingcontainer to the system to manually dispense fluid into bandage 14. Itis appreciated, however, that port 98 is configured to be closed whileno syringe is attached to maintain a closed system.

[0043] The syringe and drive are illustrated as one approach forproviding a fluid source and a drive for irrigating a wound bed. It willbe appreciated that containers other than syringes may be operated by adrive to expel irrigation fluid toward a wound surface. For example, anytype of container of fluid may be squeezed or reduced in volume by adrive mechanism to expel fluid. Also, as discussed in connection withFIG. 8, a container may be held at an elevated position to provide headpressure for irrigation fluid.

[0044] Connectors 104, 106, similar to connectors 94, 96, are providedat opposed ends of evacuating tube 20. Either one or both connectors104, 106, when closed, block flow from bandage 14 to waste canister 26.Such connectors 104, 106 also allow the patient to be disconnected fromapparatus 2 without having to remove bandage 14 or having to shut downapparatus 2.

[0045] Waste canister sensors 116, 118 are engaged when waste container26 is properly seated in apparatus 2. This prevents apparatus 2 fromoperating without canister 26 seated properly in apparatus 2. Asdepicted in FIG. 2, both sensors 116, 118 provide feedback to controller50 through lines 120, 122, confirming to the caregiver that canister 26is seated properly in apparatus 2.

[0046] In the illustrated embodiment, waste canister 26 is a disposableunit that “snaps into” side portion 38 of housing 4. (See also FIGS. 1and 6.) Illustratively, canister 26 includes a window (not shown) toallow monitoring of the fluids. Illustratively, the fluid capacity ofcanister 26 is about 500-ml.

[0047] The illustrated embodiment of waste canister 26 further includesa hydrophobic filter 108 that is in communication with both evacuatingtube 20 and vacuum pump 110. (See also FIG. 6.) Such filter 108 isconfigured to allow air, but not liquid, to pass. Accordingly, as fluidis drawn into canister 26, fluid is deposited into waste canister 26while the vacuum continues through filter 108 and pump 110.Illustratively, filter 108 is a 0.2-micron hydrophobic bacteria filterfixed into rear wall 407 of canister 26. (See FIG. 6.) Hydrophobicfilter 108 also serves as a canister full mechanism 114 or valve thatshuts off the vacuum supply to the canister 26 when the fluid levelexceeds the “full” level 420. Because hydrophobic filter 108 preventsfluid from passing, once fluid covers filter 108, vacuum is preventedfrom passing as well. The absence of any vacuum in the system will causethe system to shut down.

[0048] Vacuum pump 110 creates the negative pressure that is presentthrough canister 26. For monitoring and controlling such negativepressure, the vacuum is present through several devices, including avacuum pressure transducer 124. Transducer 124 is coupled to line 128,extending from canister 26. (See FIG. 5.) Transducer 124 measures thenegative pressure that is present through canister 26. Transducer 124then provides feedback to controller 50 through line 128. Controller 50monitors the negative pressure by comparing the measured value fromtransducer 124 with the caregiver-defined value entered into controller50 through user interface 10.

[0049] A proportional valve 130 is connected to line 126, through whichthe negative pressure is present, and which comprises a flow orifice132. (See also FIG. 5.) Flow orifice 132 selectively dilates orconstricts, thereby controlling the negative pressure level throughsub-system 66. Specifically, controller 50 provides a signal input toproportional valve 130 based on the level of the vacuum pressuredetermined from feedback of transducer 124 and comparing that level tothe caregiver-defined level. Orifice 132 then dilates or constricts, asnecessary, to produce the appropriate level of negative pressure.Illustratively, proportional valve 130 is fully constricted or closedwhen receiving no signal from controller 50, and dilates or opens toallow an illustrative maximum of two liters per minute at 250-mmHg(4.83-PSIG) vacuum when the proper signal from controller 50 is applied.

[0050] A vacuum regulator 134 is provided in line 126 betweenproportional valve 130 and pump 110 as a mechanical limit control forpump 110. Regulator 134 mechanically establishes a maximum level ofnegative pressure that is present in the system. Thus, vacuum pump 110will not physically be able to draw a vacuum from bandage 14 beyond themaximum pressure. Illustratively, such maximum negative pressure orvacuum is 250-mmHg (4.83-PSIG). In addition, when proportional valve130, pursuant to a signal from controller 50, creates a negativepressure less than the maximum negative pressure level, a port 136,coupled to regulator 134, opens so that pump 110 can draw more air tomaintain a sufficient flow through pump 110, to prevent it from becomingdamaged. A first air filter 137 is illustratively associated with port136, between port 136 and pump 110, to filter particulates from the airprior to reaching pump 110. Illustratively, filter 137 is constructed ofglass microfibers with a filtration rating of 25 microns. A secondfilter 139 is associated with pump 110 and an outlet 141. Filter 139serves as an exhaust muffler for the air evacuated from pump 110.

[0051] Vacuum pump 110 is, illustratively, a diaphragm-type compressorthat flows about two liters per minute at 250-mmHg (4.83-PSIG) vacuum.Illustratively, vacuum pump 110 is mounted on the end of a single 12VDCbrushless motor 138 to drive the pump. It is appreciated, however, thatpump 110 can be of any other configuration, and mounted in any manner,so long as it draws a desired negative pressure through system 6. It isalso contemplated that a vacuum pump external to the housing 4 may be apart of the control system. For example, most medical facilities havevacuum ports near where patients are treated, each of which is served bya system vacuum (suction) pump. It is contemplated, therefore, that thepump 110 in the housing 4 may be an appropriate fitting which is, inturn, connected to a facility vacuum pump to provide a vacuum source tothe control system.

[0052] It is contemplated that port 136, filters 137, 139, electricmotor 138, vacuum pump 110, and vacuum regulator 134 are all housed in asound chamber 140. Illustratively, the interior of sound chamber 140 islined with a damping foil like the 3M Company's damping foil number2552, for example. Sound chamber 140 dampens vibration energy producedby these components, as well as assists in dissipating heat theygenerated.

[0053] As previously indicated, it is contemplated that controller 50,user interface 10, power supply 56, and attitude sensor 58 are commonto, and operate with, both fluid dispensing and vacuum evacuatingsub-systems 62, 64 and 66, 68. Providing a second independently operableset of sub-systems 64, 68 allows the caregiver to treat two wounds usinga single apparatus 2. Accordingly, second fluid dispensing andevacuating sub-systems 64, 68 also shown in FIG. 2, comprise identicalcomponents as discussed regarding sub-systems 62, 66 and are labeled ina corresponding manner. For example, syringe motor drive 72 insub-system 62 is identified as syringe motor drive 172 in sub-system 64,and a vacuum pump 110 in sub-system 66 is identified as vacuum pump 210in sub-system 68.

[0054] A schematic diagram of a portion of wound treatment apparatus 2is shown in FIG. 3. Each system 6 and 8 is configured to operate in thesame manner. Specifically, FIG. 3 depicts the operation of system 6.Movement of plunger 70 into syringe 24 causes fluid stored in syringe 24to exit into tube 18 and into bandage 314 where it drains throughorifices 302 onto wound 300. Vacuum 110 applies a negative pressurethrough waste canister 26 and bandage 314. Fluid and exudate are thendrawn from wound 300 out through tube 20 and into canister 26. Thehydrophobic filter 108, discussed in connection with FIG. 2, allows thevacuum to pass through waste canister 26, yet, prevents any of the fluidfrom escaping, and depositing the fluid into pump 110.

[0055] The mechanism for moving plunger 70 into syringe 24, part offluid dispensing sub-system 62, is shown in cross-sectional form in FIG.4. The illustrated embodiment includes sub-system 62 positioned withinhousing 4. Specifically, a bracket frame 310 serves as the skeletalstructure for sub-system 62. Bracket 310 includes a base portion 312with an upwardly extending structural member 314 appending from one endthereof. A support portion 316 extends outwardly from member 314, and issuperposed above base portion 312. Extending from support portion 316 issyringe bracket 318. Syringe capture mechanism 88 is formed in bracket318, and is configured to receive syringe 24, as previously discussed.Bracket 318 and capture mechanism 88 are configured to suspend syringe24 with luer-lok port 22 directed upwardly. It is contemplated thatcapture mechanism 88 secures syringe 24 to bracket 318 by other means,including being friction-fitted, or secured with clips or bolts. To moveplunger 70, syringe drive 74 and plunger interface 78 are coupled toframe 310. Plunger interface 78 captures plunger 70 and provides upwardlinear motion to evacuate syringe 24. Interface 78 provides a releasemechanism for plunger 70 to remove syringe 24 at any position in thestroke.

[0056] Syringe drive 74 comprises syringe drive motor 72 and power screw322. Power screw 322 is disposed through an aperture 324 in supportportion 316, and is rotatably coupled to motor 72. It is appreciatedthat motor 72 can be a stepper or electric motor, for example. The lowerend 326 of power screw 322 is positioned within a bearing cavity 328within which power screw 322 rotates. Spaced in parallel to power screw322 is guide 80. Guide 80 is received in an aperture 330, also disposedin support portion 316 at its upper end 332, and is received in cavity334 at its lower end 336. Plunger interface 78 is configured to receivecap 338 of plunger 70, and is coupled to a dual coupler 340. Dualcoupler 340 comprises two blocks 342, 344, each having bores 346, 348disposed, respectively, there through. In the illustrated embodiment,bore 346 has a smooth surface and is configured to receive guide 80. Incontrast, bore 348 has a threaded surface and is configured to cooperatewith threads on power screw 322. Coupler 340 is movable upwardly anddownwardly in directions 350, 352. A hatched outline version of coupling340, indicated by reference numeral 354, is shown depicting plungerinterface 78 and plunger 70 moving upwardly in direction 350. As shownin FIG. 4, as plunger 70 is moved upwardly, head 356 is also movedupwardly, reducing the available space in syringe 24, thus, displacingany fluid in syringe 24 out of luer-lock port 22, thereby dispensing thefluid into tube 18 and into bandage 14. The movement of cap 356 isdepicted by the position of cap 356 in hatched lines moved to an upperposition indicated by reference numeral 358.

[0057] A cross-sectional view of waste canister 26 located in cavity 9on side 38 of housing 4 is shown in FIG. 6. Tube 20 is connected to acheck-valve assembly 400 coupled to recess 402 disposed in the frontwall 405 of canister 26. Check valve 400 is configured to allow fluidand exudate from bandage 14 to enter canister 26 and deposit in holdingspace 404 within canister 26, yet prevent any fluid already in space 404from exiting through valve 400. Check valve 400, thus prevents fluidfrom escaping when tube 20 is disengaged from valve 400. In addition,canister 26 can be discarded without any fluid escaping. Hydrophobicfilter 108 is located on the rear wall 407 of canister 26. A liquidsolidifier 29 is provided in space 404 to decease the fluidity of theexudate. This is a safety measure to lessen the chance of splashing orrun-off if canister 26 (or 27) is opened or broken.

[0058] Filter 108 in canister 26 is shown having an inlet 410 providedin space 404 and an outlet 412 coupled to a connector 416 with a barrierof hydrophobic material 414 provided there between. As previouslydiscussed, the hydrophobic material allows the vacuum to pass throughinlet 410 and outlet 412, yet prevents any fluid from passing. Similarto check valve 400, hydrophobic filter 108 too prevents any fluid fromescaping even when canister 26 is removed from housing 4. Outlet 412 offilter 108 is in communication with connector 416. Connector 416 isconfigured to receive and seal outlet 412 when canister is positioned incavity 9. Connector 416 is in communication with line 126 and ultimatelywith pump 110.

[0059] In the illustrated embodiment, hydrophobic filter 108 serves asboth the canister full mechanism 114 that shuts off the vacuum supply tothe canister 26 when the fluid level exceeds the “full” level asindicated by reference numeral 420. When the fluid level is below inlet410, as indicated by reference numeral 422, fluid continues to enterspace 404 through valve 400. When the fluid level 420 is above inlet410, the fluid is acting as an air block. Fluid cannot pass throughfilter 108, but because the fluid level is above inlet 410, air cannotpass through either. This causes a dramatic pressure drop (vacuumincrease) through line 126. Vacuum pressure transducer 124 is coupled toline 126 measuring the negative pressure passing through canister 26, aspreviously discussed. If such a dramatic pressure drop occurs,transducer 124 will provide such data to controller 50 through line 128.Controller 50 will then know to shut the system down until the fullcanister is replaced with either an empty or only a partially fallcanister.

[0060] Another illustrative embodiment of a wound treatment apparatus isshown in FIG. 8 and is indicated by reference numeral 3. Apparatus 3operates in a similar manner as apparatus 2, with the exception of theuse of two “intravenousstyle” fluid bags 510, 512 suspended abovehousing 4 to dispense the fluid. In this illustrated embodiment, posts514, 516 with hooks 518, 520 extend upwardly of apparatus 3 from behinddoors 32, 33. It will be appreciated that the posts 514, 516 may beextensible to elevate the bags 510, 512 to selected heights to provideselected pressures for irrigation. A dispensing tube 18 extends fromeach bag 510, 512 at one end and couples to each bandage. Gravityassists in moving fluid through tubes 18 and into the bandages. A tubeclip 522 is coupled to each tube 18 and configured to pinch and closetube allowing the caregiver to selectively prevent fluid from dispensinginto bandages.

[0061] Illustrative vacuum bandage 314 of FIG. 3 is designed to providea protective environment around wound 300. Illustratively, such bandageslast for up to 7 days without having to be replaced. Bandage 314includes rinse and drain orifices (not shown) within the body of bandage314 that communicate with tubes 18, 20, respectively. Such orifices areillustratively 0.070-inch (0.18 cm) diameter. Vacuum evacuatingsub-system 66 cooperates with bandage 314, similar to bandage 14, todraw the fluid and exudate from the surface of wound 300, and collectsame into waste canister 26.

[0062] Examples of bandages 14 and 15 are shown in U.S. patentapplication Ser. No. ______, entitled VACUUM THERAPY AND CLEANSINGDRESSING FOR WOUNDS, filed concurrently with the present disclosure onNov. 29, 2000, and assigned to the same Assignee or Affiliated Assigneeas the present disclosure, and the complete disclosure of which ishereby expressly incorporated by reference. It is further contemplatedthat other bandages may be used with this control system, includingbandages having separate irrigation and vacuum ports. Examples of suchbandages are shown in U.S. patent application Ser. No. 09/369,113,entitled WOUND TREATMENT APPARATUS, filed on Aug. 5, 1999, and assignedto the same Assignee or Affiliated Assignee as the present disclosure,and the complete disclosure of which is hereby expressly incorporated byreference.

[0063] A side diagrammatic view of bandage 14 along with a portion ofsystem 6 is shown in FIG. 9. (See also FIG. 1.) Bandage 14 is of anillustrative type for use with apparatus 2. (Note that the bandage isnot drawn to scale.) As previously discussed, bandage 14 is a vacuumbandage. Bandage 14 comprises a cover film 602, illustratively aflexible cover, that seals wound 300 about its outer perimeter. It iscontemplated, however, that film 602 can be made from an occlusive orsemi-occlusive material that allows water vapor to permeate therethrough, but otherwise protects wound 300 from the outside environment.A bandage member 604 is placed adjacent wound 300 and is configured toirrigate wound 300. In the illustrated embodiment, bandage member 604comprises upper channels 606 and lower channels 608, each provided onopposite sides 610, 612, respectively, of bandage member 604. Each ofthe upper channels 606 is generally congruent with one of the lowerchannels 608. Channels 606 and 608 are in communication with each othervia apertures 614. As shown in the illustrated embodiment, side 612 ofbandage member 604 faces wound 300, and side 610 faces a porous packing618. Packing 618 provided under film 602 to assist in providing a space616 to facilitate the negative pressure. Packing 618 is typically agauze material.

[0064] Illustratively, the caregiver may activate system 6, by meanspreviously described, to draw exudate from wound 300 through channels606, 608 and apertures 614 of bandage member 604, packing 618 and film602, through splitter tube 620 connected to evacuating tube 20, anddeposit in canister 26. The negative pressure applied to wound 300created by pump 110 can be applied for a period of time as determined bythe caregiver. After a period of drawing, the caregiver may deactivatethe negative pressure. The caregiver may begin irrigating wound 300 byreleasing fluid from syringe 24, through tube 18, into splitter tube620, through film 602 and packing 618, and into bandage member 604. Thefluid will travel through channels 606 deposit in apertures 614 andirrigate wound 300 by traveling through channels 608. Illustratively,the fluid will continue to irrigate wound 300 until space 616 can nolonger receive any more fluid. The fluid is held in space 616 for aperiod of time as determined by the caregiver. After that period, pump110 is reactivated and the fluid and exudate from wound 300 is evacuatedfrom bandage 14 and into canister 26 by the manner previously described.This process is repeated as many times as necessary as determined by thecaregiver.

[0065] In one embodiment, user interface 10 comprises a momentary switch(not shown) that selectively operates the aforementioned process. Forexample, the switch may be configured such that when the caregiverdepresses and holds the switch, the fluid will dispense from syringe 24into bandage 14. When the caregiver releases the switch the fluid willstop dispensing and pump 110 will activate and begin drawing the fluidand exudate. It is contemplated that the switch may be configured todelay between the vacuuming and dispensing for a period of time that isdefinable by the caregiver. It is also contemplated that all of theaforementioned descriptions as applied to system 6 are applicable tosystem 8.

[0066] The apparatus 2 is a portable, easy to use topical system that isintended to provide a protective/occlusive environment with features tofacilitate the administering of standard wound care. The apparatus 2provides for the care of two independently controlled wounds. Theapparatus 2 provides negative pressure to the wound bed, and thecaregiver can set the level of negative pressure. Illustratively, thenegative pressure is variable from 25-mmHg to 225-mmHg at increments of10-mmHg. The caregiver can choose between continuous, intermittent(profile), and no negative pressure modes. It will be appreciated thatthe apparatus 2 may be set up to provide various levels of vacuum atvarious times. The apparatus may be provided with the ability to pausenegative pressure therapy for set durations of time. The system may beset up to provide audible alarms to remind the caregiver to reset orstart a new cycle of vacuum therapy.

[0067] The apparatus 2 is intended to provide an occlusive wound healingenvironment. The apparatus 2 provides an active therapy unit thatdelivers drainage and cleansing for aggressive wound healing. It isintended, for example, for use on all pressure ulcers (Stage II throughStage IV), surgical draining wounds and leg ulcers.

[0068] In the illustrated embodiment, as shown in FIGS. 7 and 10, forexample, canister 26 is configured to be received in cavity 9 disposedin side 38 of housing 4. As shown specifically in FIG. 10, cavity 9comprises two pull recesses 702, 704. Such recesses 702, 704 areconcave-shaped portions formed adjacent to side 38 and to side walls 706and 708. Recesses 702, 704 are provided to allow finger clearance whenthe caregiver grasps grip portions 39, 40 of canister 26 to remove itfrom, or insert it into cavity 9. (See also FIGS. 1, 11 and 13.) Sidewalls 706, 710 and bottom and top walls 708, 712 define cavity 9 suchthat cavity 9 provides a relatively conforming receptacle for thecanister 26. The walls 706, 710 and 708, 712 conform to the size andshape of the panels 714, 716, 718, 720 of canister 26. (See FIGS. 12 and13.) Outlet 412 of filter 108 mates with connector 416 to produce anair-tight seal between port 412 and connector 416. It is furthercontemplated that other structures or configurations of outlet 412 andconnector 416 can be used to ensure system 6 is a closed system whencanister 26 is properly coupled to housing 4. It is still furthercontemplated that the aforementioned descriptions of canister 26 ofsystem 6 apply equally to canister 27 of system 8.

[0069] Each of top and bottom panel 718, 720 of canister 26 includes aboss 722, 724, respectively. Each boss 722, 724 is configured to engagea sensor such as sensor 116, 118, respectively, as depicted in FIG. 2.This engagement provides a signal to controller 50 indicating thatcanister 26 is seated properly into cavity 9 and the vacuum therapytreatment may begin to be administered. It is contemplated that bosses722, 724 can be mechanical sensors, optical, capacitive or other similartype sensors.

[0070] Side panels 714, 716 include buttons 726, 728 to assist thecaregiver in placing canister 26 in the proper location within cavity 9.Illustratively, buttons 726, 728 are small protrusions, each extendingfrom a side panel. Each button 726, 728 is configured to be received or“snapped” into corresponding dimples 730, 732, respectively, disposed inwalls 706, 710, respectively. In the illustrated embodiment, the buttonsextend from the widest point of side panels 714, 716 of canister 26.

[0071] Although the foregoing apparatus has been described, one skilledin the art can easily ascertain the essential characteristics of theapparatus, and various changes and modifications may be made to adaptthe various uses and characteristics without departing from the spiritand scope of this disclosure, as described by the claims which follow.

1. For use with a bandage of the type which covers a wound and withinwhich a vacuum is formed in a space above the wound, a control systemcomprising: a vacuum pump; a waste canister to be operably coupled tothe pump; a fluid source; a drive associated with the fluid source; thecanister to be coupled to the bandage such that, when a vacuum isapplied to the canister, the vacuum is applied to the bandage; and thefluid source to be coupled to the bandage such that, when the drive isenergized, fluid is introduced into the wound.
 2. The control system ofclaim 1, in which the fluid source is a syringe to be coupled to thecontrol system, the syringe including a plunger, and the drive beingconfigured to drive the plunger to expel fluid from the syringe.
 3. Thecontrol system of claim 2, in which the drive comprises a motor and aplunger interface movable by the motor to drive the plunger.
 4. Thecontrol system of claim 3, wherein the motor is a stepper motor.
 5. Thecontrol system of claim 4, wherein the stepper motor is operativelycoupled to a lead screw for rotating the lead screw, the lead screw alsobeing operatively coupled to the plunger interface to move the plungerinterface to drive the plunger.
 6. The control system of claim 5,comprising a sensor coupled to the drive to detect movement of theplunger.
 7. The control system of claim 2, wherein a connector isprovided to allow operation of the control system when the syringe iscoupled to the control system, and to suspend operation of the controlsystem when the syringe is removed from the control system.
 8. Thecontrol system of claim 1, comprising a valve between the waste canisterand the vacuum pump, the valve being adjustable to establish the levelof vacuum in the canister.
 9. The control system of claim 8, wherein thevalve is a proportional valve.
 10. The control system of claim 8,comprising a vacuum regulator connected to the valve, the regulatorbeing configured to define a maximum level of vacuum.
 11. The controlsystem of claim 10, wherein the regulator comprises an air intake tosupply additional air to the pump.
 12. The control system of claim 11,comprising a transducer coupled between the valve and the waste canisterto measure pressure.
 13. The control system of claim 1, comprising ahydrophobic filter coupled between the waste canister and the pump toblock liquid flow from the waste canister toward the pump.
 14. Thecontrol system of claim 13, wherein the hydrophobic filter is positionedin the waste canister and coupled between the waste canister and thepump to block vacuum flow when the waste canister is full.
 15. Thecontrol system of claim 1, in which the waste canister and the fluidsource are disposable accessories to be coupled to the control system.16. The control system of claim 1, comprising a sensor coupled with thewaste canister to detect when the canister is full.
 17. The controlsystem of claim 1, comprising two such vacuum pumps, two such wastecanisters, two such fluid sources and two such drives for use with twosuch bandages, thereby providing dual vacuum therapy and irrigationsystems.
 18. The control system of claim 17, in which the control systemto provide for independent operation of the dual systems.
 19. For usewith a vacuum bandage of the type which covers a wound and within whicha vacuum is formed in the space above the wound, and comprising acontroller configured to apply a vacuum to the bandage, the controllercomprising a syringe plunger driver, a vacuum pump, a canister mount anda syringe mount configured to hold a syringe, disposables comprising: awaste canister configured to be mated with the canister mount; and atube set configured to be coupled to the waste canister, the syringe,and the bandage; the tube set being configured operatively to couple thepump to the bandage through the canister, and to couple the syringe tobandage.
 20. The disposables of claim 19, comprising a pair of wastecanisters to be mated with a pair of canister mounts for use with a pairof bandages, and the tube set to be coupled to each of the wastecanisters and each of the bandages.
 21. A controller for a vacuumbandage, the controller comprising: a vacuum pump to be coupled to thebandage; a syringe mount configured to hold a syringe of the type havinga plunger for expelling fluid from the syringe to the bandage; and adrive for the plunger.
 22. The controller of claim 21, comprising aconnector to allow operation of the controller when the syringe iscoupled to the syringe mount, and to suspend operation of the controllerwhen the syringe is removed from the syringe mount.
 23. The controllerof claim 21, comprising a waste canister mount configured to hold awaste canister for receiving exudate from the bandage.
 24. Thecontroller of claim 21, comprising two such vacuum pumps, two suchsyringe mounts, and two such drives to provide dual vacuum therapy andirrigation systems.
 25. The controller of claim 24, being configured toprovide independent operation of the dual systems.
 26. The controller ofclaim 25, comprising two such waste canister mounts.
 27. A controlsystem for a vacuum bandage, the control system comprising: a housingcomprising a pair of vacuum pumps, a pair of syringe mounts, a pair ofsyringe drives, and a pair of waste canister mounts; a controller toprovide independent operation of the vacuum pumps; a pair of wastecanisters each removably attached to one of the canister mounts, and incommunication with the bandage and one of the vacuum pumps; and a pairof syringes each removably attached to one of the syringe mounts, and incommunication with the bandage.
 28. The control system of claim 27,wherein the waste canister and syringes are disposable.
 29. The controlsystem of claim 27, configured to allow operation of the controller whenat least one of the syringes is coupled to one of the syringe mounts,and suspend operation of the controller when at least one of thesyringes is removed from one of the syringe mounts.
 30. For use with abandage of the type which covers a wound and within which a vacuum isformed in a space above the wound, a control system comprising: a vacuumpump; a waste canister to be operably coupled to the pump; and a fluidsource; the canister to be coupled to the bandage such that, when avacuum is applied to the canister, the vacuum is applied to the bandage;and the fluid source to be held at an elevated position relative to thecontrol system to provide a desired fluid pressure to introduce fluid tothe wound for irrigation of the wound.
 31. For use with a controlapparatus providing a vacuum source and a shaped cavity having a suctionport leading to the vacuum, and a bandage of the type which covers awound and within which a vacuum, generated by the control apparatus, isformed in a space above the wound, a canister comprising: a containerconfigured and shaped to be inserted into the shaped cavity; thecontainer having an inlet port to be in communication with the bandage,the inlet port configured to receive fluid and exudate from the woundand deposit the fluid and exudate in the container; and the containerhaving an outlet port positioned to engage the suction port of thecontrol apparatus, the outlet port configured to introduce the vacuumfrom the control apparatus to the container.
 32. The canister of claim31, wherein the inlet port includes a valve to prevent fluid in thecontainer from exiting the canister.
 33. The canister of claim 32,wherein the valve is a check valve.
 34. The canister of claim 31,wherein the outlet port includes a filter that prevents fluid in thecontainer from exiting the canister.
 35. The canister of claim 34,wherein the filter is a hydrophobic filter.
 36. The canister of claim31, wherein the vacuum is introduced to the bandage from the inlet port.37. The canister of claim 34, wherein the inlet port is provided abovethe outlet port relative to a plane defined by the level of fluidcollected in the container.
 38. The canister of claim 37, such that whenthe level of fluid is positioned above the outlet port, the vacuum iscaused to cease, indicating that the container is fall.
 39. The canisterof claim 31, further comprising a liquid solidifier material in thecontainer.
 40. The canister of claim 37, wherein the canister is adisposable canister.
 41. The canister of claim 38, wherein the outletport communicates with a vacuum pump in the control apparatus.
 42. Thecanister of claim 33, wherein the inlet port communicates with a tubecoupled to the bandage, the tube being configured to receive fluid andexudate from the wound.
 43. The canister of claim 31, in which thecanister is further configured and shaped with a hand grip toselectively remove the canister from the cavity.
 44. The canister ofclaim 31, in which the container is further configured and shaped toprovide an air-tight seal between the container and the cavity.